refactor logger: move some independent methods into separate util file

src/modules/logger/CMakeLists.txt

@@ -42,6 +42,7 @@ px4_add_module(
 		log_writer.cpp
 		log_writer_file.cpp
 		log_writer_mavlink.cpp
+		util.cpp
 		watchdog.cpp
 	DEPENDS
 		version

src/modules/logger/logger.cpp

@@ -49,7 +49,6 @@
 #include <uORB/topics/log_message.h>
 #include <uORB/topics/parameter_update.h>
 #include <uORB/topics/vehicle_status.h>
-#include <uORB/topics/vehicle_gps_position.h>
 #include <uORB/topics/vehicle_command_ack.h>
 
 #include <drivers/drv_hrt.h>
@@ -64,17 +63,6 @@
 #include <replay/definitions.hpp>
 #include <version/version.h>
 
-#if defined(__PX4_DARWIN)
-#include <sys/param.h>
-#include <sys/mount.h>
-#else
-#include <sys/statfs.h>
-#endif
-
-typedef decltype(statfs::f_bavail) px4_statfs_buf_f_bavail_t;
-
-#define GPS_EPOCH_SECS ((time_t)1234567890ULL)
-
 //#define DBGPRINT //write status output every few seconds
 
 #if defined(DBGPRINT)
@@ -824,7 +812,13 @@ void Logger::run()
 			}
 		}
 
-		if (check_free_space() == 1) {
+		int32_t max_log_dirs_to_keep = 0;
+
+		if (_log_dirs_max != PARAM_INVALID) {
+			param_get(_log_dirs_max, &max_log_dirs_to_keep);
+		}
+
+		if (util::check_free_space(LOG_ROOT, max_log_dirs_to_keep, _mavlink_log_pub, _sess_dir_index) == 1) {
 			return;
 		}
 	}
@@ -1363,20 +1357,20 @@ int Logger::create_log_dir(tm *tt)
 	return 0;
 }
 
-bool Logger::file_exist(const char *filename)
-{
-	struct stat buffer;
-	return stat(filename, &buffer) == 0;
-}
-
 int Logger::get_log_file_name(char *file_name, size_t file_name_size)
 {
 	tm tt = {};
 	bool time_ok = false;
 
 	if (_log_name_timestamp) {
+		int32_t utc_offset = 0;
+
+		if (_log_utc_offset != PARAM_INVALID) {
+			param_get(_log_utc_offset, &utc_offset);
+		}
+
 		/* use RTC time for log file naming, e.g. /fs/microsd/2014-01-19/19_37_52.ulg */
-		time_ok = get_log_time(&tt, false);
+		time_ok = util::get_log_time(&tt, utc_offset * 60, false);
 	}
 
 	const char *replay_suffix = "";
@@ -1409,7 +1403,7 @@ int Logger::get_log_file_name(char *file_name, size_t file_name_size)
 			snprintf(_log_file_name, sizeof(_log_file_name), "log%03u%s.ulg", file_number, replay_suffix);
 			snprintf(file_name, file_name_size, "%s/%s", _log_dir, _log_file_name);
 
-			if (!file_exist(file_name)) {
+			if (!util::file_exist(file_name)) {
 				break;
 			}
 
@@ -1435,57 +1429,6 @@ void Logger::setReplayFile(const char *file_name)
 	_replay_file_name = strdup(file_name);
 }
 
-bool Logger::get_log_time(struct tm *tt, bool boot_time)
-{
-	int vehicle_gps_position_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
-
-	if (vehicle_gps_position_sub < 0) {
-		return false;
-	}
-
-	/* Get the latest GPS publication */
-	vehicle_gps_position_s gps_pos;
-	time_t utc_time_sec;
-	bool use_clock_time = true;
-
-	if (orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_position_sub, &gps_pos) == 0) {
-		utc_time_sec = gps_pos.time_utc_usec / 1e6;
-
-		if (gps_pos.fix_type >= 2 && utc_time_sec >= GPS_EPOCH_SECS) {
-			use_clock_time = false;
-		}
-	}
-
-	orb_unsubscribe(vehicle_gps_position_sub);
-
-	if (use_clock_time) {
-		/* take clock time if there's no fix (yet) */
-		struct timespec ts = {};
-		px4_clock_gettime(CLOCK_REALTIME, &ts);
-		utc_time_sec = ts.tv_sec + (ts.tv_nsec / 1e9);
-
-		if (utc_time_sec < GPS_EPOCH_SECS) {
-			return false;
-		}
-	}
-
-	/* strip the time elapsed since boot */
-	if (boot_time) {
-		utc_time_sec -= hrt_absolute_time() / 1e6;
-	}
-
-	int32_t utc_offset = 0;
-
-	if (_log_utc_offset != PARAM_INVALID) {
-		param_get(_log_utc_offset, &utc_offset);
-	}
-
-	/* apply utc offset */
-	utc_time_sec += utc_offset * 60;
-
-	return gmtime_r(&utc_time_sec, tt) != nullptr;
-}
-
 void Logger::start_log_file()
 {
 	if (_writer.is_started(LogWriter::BackendFile) || (_writer.backend() & LogWriter::BackendFile) == 0) {
@@ -2053,187 +1996,6 @@ void Logger::write_changed_parameters()
 	_writer.notify();
 }
 
-int Logger::check_free_space()
-{
-	struct statfs statfs_buf;
-
-	int32_t max_log_dirs_to_keep = 0;
-
-	if (_log_dirs_max != PARAM_INVALID) {
-		param_get(_log_dirs_max, &max_log_dirs_to_keep);
-	}
-
-	if (max_log_dirs_to_keep == 0) {
-		max_log_dirs_to_keep = INT32_MAX;
-	}
-
-	// remove old logs if the free space falls below a threshold
-	do {
-		if (statfs(LOG_ROOT, &statfs_buf) != 0) {
-			return PX4_ERROR;
-		}
-
-		DIR *dp = opendir(LOG_ROOT);
-
-		if (dp == nullptr) {
-			break; // ignore if we cannot access the log directory
-		}
-
-		struct dirent *result = nullptr;
-
-		int num_sess = 0, num_dates = 0;
-
-		// There are 2 directory naming schemes: sess<i> or <year>-<month>-<day>.
-		// For both we find the oldest and then remove the one which has more directories.
-		int year_min = 10000, month_min = 99, day_min = 99, sess_idx_min = 99999999, sess_idx_max = 0;
-
-		while ((result = readdir(dp))) {
-			int year, month, day, sess_idx;
-
-			if (sscanf(result->d_name, "sess%d", &sess_idx) == 1) {
-				++num_sess;
-
-				if (sess_idx > sess_idx_max) {
-					sess_idx_max = sess_idx;
-				}
-
-				if (sess_idx < sess_idx_min) {
-					sess_idx_min = sess_idx;
-				}
-
-			} else if (sscanf(result->d_name, "%d-%d-%d", &year, &month, &day) == 3) {
-				++num_dates;
-
-				if (year < year_min) {
-					year_min = year;
-					month_min = month;
-					day_min = day;
-
-				} else if (year == year_min) {
-					if (month < month_min) {
-						month_min = month;
-						day_min = day;
-
-					} else if (month == month_min) {
-						if (day < day_min) {
-							day_min = day;
-						}
-					}
-				}
-			}
-		}
-
-		closedir(dp);
-
-		_sess_dir_index = sess_idx_max + 1;
-
-
-		uint64_t min_free_bytes = 300ULL * 1024ULL * 1024ULL;
-		uint64_t total_bytes = (uint64_t)statfs_buf.f_blocks * statfs_buf.f_bsize;
-
-		if (total_bytes / 10 < min_free_bytes) { // reduce the minimum if it's larger than 10% of the disk size
-			min_free_bytes = total_bytes / 10;
-		}
-
-		if (num_sess + num_dates <= max_log_dirs_to_keep &&
-		    statfs_buf.f_bavail >= (px4_statfs_buf_f_bavail_t)(min_free_bytes / statfs_buf.f_bsize)) {
-			break; // enough free space and limit not reached
-		}
-
-		if (num_sess == 0 && num_dates == 0) {
-			break; // nothing to delete
-		}
-
-		char directory_to_delete[LOG_DIR_LEN];
-		int n;
-
-		if (num_sess >= num_dates) {
-			n = snprintf(directory_to_delete, sizeof(directory_to_delete), "%s/sess%03u", LOG_ROOT, sess_idx_min);
-
-		} else {
-			n = snprintf(directory_to_delete, sizeof(directory_to_delete), "%s/%04u-%02u-%02u", LOG_ROOT, year_min, month_min,
-				     day_min);
-		}
-
-		if (n >= (int)sizeof(directory_to_delete)) {
-			PX4_ERR("log path too long (%i)", n);
-			break;
-		}
-
-		PX4_INFO("removing log directory %s to get more space (left=%u MiB)", directory_to_delete,
-			 (unsigned int)(statfs_buf.f_bavail * statfs_buf.f_bsize / 1024U / 1024U));
-
-		if (remove_directory(directory_to_delete)) {
-			PX4_ERR("Failed to delete directory");
-			break;
-		}
-
-	} while (true);
-
-
-	/* use a threshold of 50 MiB: if below, do not start logging */
-	if (statfs_buf.f_bavail < (px4_statfs_buf_f_bavail_t)(50 * 1024 * 1024 / statfs_buf.f_bsize)) {
-		mavlink_log_critical(&_mavlink_log_pub,
-				     "[logger] Not logging; SD almost full: %u MiB",
-				     (unsigned int)(statfs_buf.f_bavail * statfs_buf.f_bsize / 1024U / 1024U));
-		return 1;
-	}
-
-	return PX4_OK;
-}
-
-int Logger::remove_directory(const char *dir)
-{
-	DIR *d = opendir(dir);
-	size_t dir_len = strlen(dir);
-	struct dirent *p;
-	int ret = 0;
-
-	if (!d) {
-		return -1;
-	}
-
-	while (!ret && (p = readdir(d))) {
-		int ret2 = -1;
-		char *buf;
-		size_t len;
-
-		if (!strcmp(p->d_name, ".") || !strcmp(p->d_name, "..")) {
-			continue;
-		}
-
-		len = dir_len + strlen(p->d_name) + 2;
-		buf = new char[len];
-
-		if (buf) {
-			struct stat statbuf;
-
-			snprintf(buf, len, "%s/%s", dir, p->d_name);
-
-			if (!stat(buf, &statbuf)) {
-				if (S_ISDIR(statbuf.st_mode)) {
-					ret2 = remove_directory(buf);
-
-				} else {
-					ret2 = unlink(buf);
-				}
-			}
-
-			delete[] buf;
-		}
-
-		ret = ret2;
-	}
-
-	closedir(d);
-
-	if (!ret) {
-		ret = rmdir(dir);
-	}
-
-	return ret;
-}
-
 void Logger::ack_vehicle_command(orb_advert_t &vehicle_command_ack_pub, vehicle_command_s *cmd, uint32_t result)
 {
 	vehicle_command_ack_s vehicle_command_ack = {};

src/modules/logger/logger.h

@@ -35,6 +35,7 @@
 
 #include "log_writer.h"
 #include "array.h"
+#include "util.h"
 #include <px4_defines.h>
 #include <drivers/drv_hrt.h>
 #include <uORB/Subscription.hpp>
@@ -50,12 +51,6 @@ extern "C" __EXPORT int logger_main(int argc, char *argv[]);
 #define TRY_SUBSCRIBE_INTERVAL 1000*1000	// interval in microseconds at which we try to subscribe to a topic
 // if we haven't succeeded before
 
-#ifdef __PX4_NUTTX
-#define LOG_DIR_LEN 64
-#else
-#define LOG_DIR_LEN 256
-#endif
-
 namespace px4
 {
 namespace logger
@@ -185,26 +180,11 @@ private:
 	 */
 	int create_log_dir(tm *tt);
 
-	/** recursively remove a directory
-	 * @return 0 on success, <0 otherwise
-	 */
-	int remove_directory(const char *dir);
-
-	static bool file_exist(const char *filename);
-
 	/**
 	 * Get log file name with directory (create it if necessary)
 	 */
 	int get_log_file_name(char *file_name, size_t file_name_size);
 
-	/**
-	 * Check if there is enough free space left on the SD Card.
-	 * It will remove old log files if there is not enough space,
-	 * and if that fails return 1
-	 * @return 0 on success, 1 if not enough space, <0 on error
-	 */
-	int check_free_space();
-
 	void start_log_file();
 
 	void stop_log_file();
@@ -275,14 +255,6 @@ private:
 	 */
 	bool write_message(void *ptr, size_t size);
 
-	/**
-	 * Get the time for log file name
-	 * @param tt returned time
-	 * @param boot_time use time when booted instead of current time
-	 * @return true on success, false otherwise (eg. if no gps)
-	 */
-	bool get_log_time(struct tm *tt, bool boot_time = false);
-
 	/**
 	 * Parse a file containing a list of uORB topics to log, calling add_topic for each
 	 * @param fname name of file

src/modules/logger/util.cpp

+/****************************************************************************
+ *
+ *   Copyright (c) 2018 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#include "util.h"
+
+#include <dirent.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include <uORB/topics/vehicle_gps_position.h>
+
+#include <drivers/drv_hrt.h>
+#include <px4_log.h>
+#include <px4_time.h>
+#include <systemlib/mavlink_log.h>
+
+#if defined(__PX4_DARWIN)
+#include <sys/param.h>
+#include <sys/mount.h>
+#else
+#include <sys/statfs.h>
+#endif
+
+#define GPS_EPOCH_SECS ((time_t)1234567890ULL)
+
+typedef decltype(statfs::f_bavail) px4_statfs_buf_f_bavail_t;
+
+namespace px4
+{
+namespace logger
+{
+namespace util
+{
+
+bool file_exist(const char *filename)
+{
+	struct stat buffer;
+	return stat(filename, &buffer) == 0;
+}
+
+bool get_log_time(struct tm *tt, int utc_offset_sec, bool boot_time)
+{
+	int vehicle_gps_position_sub = orb_subscribe(ORB_ID(vehicle_gps_position));
+
+	if (vehicle_gps_position_sub < 0) {
+		return false;
+	}
+
+	/* Get the latest GPS publication */
+	vehicle_gps_position_s gps_pos;
+	time_t utc_time_sec;
+	bool use_clock_time = true;
+
+	if (orb_copy(ORB_ID(vehicle_gps_position), vehicle_gps_position_sub, &gps_pos) == 0) {
+		utc_time_sec = gps_pos.time_utc_usec / 1e6;
+
+		if (gps_pos.fix_type >= 2 && utc_time_sec >= GPS_EPOCH_SECS) {
+			use_clock_time = false;
+		}
+	}
+
+	orb_unsubscribe(vehicle_gps_position_sub);
+
+	if (use_clock_time) {
+		/* take clock time if there's no fix (yet) */
+		struct timespec ts = {};
+		px4_clock_gettime(CLOCK_REALTIME, &ts);
+		utc_time_sec = ts.tv_sec + (ts.tv_nsec / 1e9);
+
+		if (utc_time_sec < GPS_EPOCH_SECS) {
+			return false;
+		}
+	}
+
+	/* strip the time elapsed since boot */
+	if (boot_time) {
+		utc_time_sec -= hrt_absolute_time() / 1e6;
+	}
+
+	/* apply utc offset */
+	utc_time_sec += utc_offset_sec;
+
+	return gmtime_r(&utc_time_sec, tt) != nullptr;
+}
+
+int check_free_space(const char *log_root_dir, int32_t max_log_dirs_to_keep, orb_advert_t &mavlink_log_pub,
+		     int &sess_dir_index)
+{
+	struct statfs statfs_buf;
+
+	if (max_log_dirs_to_keep == 0) {
+		max_log_dirs_to_keep = INT32_MAX;
+	}
+
+	// remove old logs if the free space falls below a threshold
+	do {
+		if (statfs(log_root_dir, &statfs_buf) != 0) {
+			return PX4_ERROR;
+		}
+
+		DIR *dp = opendir(log_root_dir);
+
+		if (dp == nullptr) {
+			break; // ignore if we cannot access the log directory
+		}
+
+		struct dirent *result = nullptr;
+
+		int num_sess = 0, num_dates = 0;
+
+		// There are 2 directory naming schemes: sess<i> or <year>-<month>-<day>.
+		// For both we find the oldest and then remove the one which has more directories.
+		int year_min = 10000, month_min = 99, day_min = 99, sess_idx_min = 99999999, sess_idx_max = 0;
+
+		while ((result = readdir(dp))) {
+			int year, month, day, sess_idx;
+
+			if (sscanf(result->d_name, "sess%d", &sess_idx) == 1) {
+				++num_sess;
+
+				if (sess_idx > sess_idx_max) {
+					sess_idx_max = sess_idx;
+				}
+
+				if (sess_idx < sess_idx_min) {
+					sess_idx_min = sess_idx;
+				}
+
+			} else if (sscanf(result->d_name, "%d-%d-%d", &year, &month, &day) == 3) {
+				++num_dates;
+
+				if (year < year_min) {
+					year_min = year;
+					month_min = month;
+					day_min = day;
+
+				} else if (year == year_min) {
+					if (month < month_min) {
+						month_min = month;
+						day_min = day;
+
+					} else if (month == month_min) {
+						if (day < day_min) {
+							day_min = day;
+						}
+					}
+				}
+			}
+		}
+
+		closedir(dp);
+
+		sess_dir_index = sess_idx_max + 1;
+
+
+		uint64_t min_free_bytes = 300ULL * 1024ULL * 1024ULL;
+		uint64_t total_bytes = (uint64_t)statfs_buf.f_blocks * statfs_buf.f_bsize;
+
+		if (total_bytes / 10 < min_free_bytes) { // reduce the minimum if it's larger than 10% of the disk size
+			min_free_bytes = total_bytes / 10;
+		}
+
+		if (num_sess + num_dates <= max_log_dirs_to_keep &&
+		    statfs_buf.f_bavail >= (px4_statfs_buf_f_bavail_t)(min_free_bytes / statfs_buf.f_bsize)) {
+			break; // enough free space and limit not reached
+		}
+
+		if (num_sess == 0 && num_dates == 0) {
+			break; // nothing to delete
+		}
+
+		char directory_to_delete[LOG_DIR_LEN];
+		int n;
+
+		if (num_sess >= num_dates) {
+			n = snprintf(directory_to_delete, sizeof(directory_to_delete), "%s/sess%03u", log_root_dir, sess_idx_min);
+
+		} else {
+			n = snprintf(directory_to_delete, sizeof(directory_to_delete), "%s/%04u-%02u-%02u", log_root_dir, year_min, month_min,
+				     day_min);
+		}
+
+		if (n >= (int)sizeof(directory_to_delete)) {
+			PX4_ERR("log path too long (%i)", n);
+			break;
+		}
+
+		PX4_INFO("removing log directory %s to get more space (left=%u MiB)", directory_to_delete,
+			 (unsigned int)(statfs_buf.f_bavail * statfs_buf.f_bsize / 1024U / 1024U));
+
+		if (remove_directory(directory_to_delete)) {
+			PX4_ERR("Failed to delete directory");
+			break;
+		}
+
+	} while (true);
+
+
+	/* use a threshold of 50 MiB: if below, do not start logging */
+	if (statfs_buf.f_bavail < (px4_statfs_buf_f_bavail_t)(50 * 1024 * 1024 / statfs_buf.f_bsize)) {
+		mavlink_log_critical(&mavlink_log_pub,
+				     "[logger] Not logging; SD almost full: %u MiB",
+				     (unsigned int)(statfs_buf.f_bavail * statfs_buf.f_bsize / 1024U / 1024U));
+		return 1;
+	}
+
+	return PX4_OK;
+}
+
+int remove_directory(const char *dir)
+{
+	DIR *d = opendir(dir);
+	size_t dir_len = strlen(dir);
+	struct dirent *p;
+	int ret = 0;
+
+	if (!d) {
+		return -1;
+	}
+
+	while (!ret && (p = readdir(d))) {
+		int ret2 = -1;
+		char *buf;
+		size_t len;
+
+		if (!strcmp(p->d_name, ".") || !strcmp(p->d_name, "..")) {
+			continue;
+		}
+
+		len = dir_len + strlen(p->d_name) + 2;
+		buf = new char[len];
+
+		if (buf) {
+			struct stat statbuf;
+
+			snprintf(buf, len, "%s/%s", dir, p->d_name);
+
+			if (!stat(buf, &statbuf)) {
+				if (S_ISDIR(statbuf.st_mode)) {
+					ret2 = remove_directory(buf);
+
+				} else {
+					ret2 = unlink(buf);
+				}
+			}
+
+			delete[] buf;
+		}
+
+		ret = ret2;
+	}
+
+	closedir(d);
+
+	if (!ret) {
+		ret = rmdir(dir);
+	}
+
+	return ret;
+}
+
+} //namespace util
+} //namespace logger
+} //namespace px4

src/modules/logger/util.h

+/****************************************************************************
+ *
+ *   Copyright (c) 2018 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+#pragma once
+
+#include <stdint.h>
+#include <time.h>
+
+#include <uORB/uORB.h>
+
+#ifdef __PX4_NUTTX
+#define LOG_DIR_LEN 64
+#else
+#define LOG_DIR_LEN 256
+#endif
+
+namespace px4
+{
+namespace logger
+{
+namespace util
+{
+
+/**
+ * Recursively remove a directory
+ * @return 0 on success, <0 otherwise
+ */
+int remove_directory(const char *dir);
+
+/**
+ * check if a file exists
+ */
+bool file_exist(const char *filename);
+
+/**
+ * Check if there is enough free space left on the SD Card.
+ * It will remove old log files if there is not enough space,
+ * and if that fails return 1, and send a user message
+ * @param log_root_dir log root directory: it's expected to contain directories in the form of sess%i or %d-%d-%d (year, month, day)
+ * @param max_log_dirs_to_keep maximum log directories to keep (set to 0 for unlimited)
+ * @param mavlink_log_pub
+ * @param sess_dir_index output argument: will be set to the next free directory sess%i index.
+ * @return 0 on success, 1 if not enough space, <0 on error
+ */
+int check_free_space(const char *log_root_dir, int32_t max_log_dirs_to_keep, orb_advert_t &mavlink_log_pub,
+		     int &sess_dir_index);
+
+/**
+ * Get the time for log file name
+ * @param tt returned time
+ * @param utc_offset_sec UTC time offset [s]
+ * @param boot_time use time when booted instead of current time
+ * @return true on success, false otherwise (eg. if no gps)
+ */
+bool get_log_time(struct tm *tt, int utc_offset_sec = 0, bool boot_time = false);
+
+} //namespace util
+} //namespace logger
+} //namespace px4